The reason why system updates cannot be performed using Yum has been under secondary development on trixbox over the past few days. trixbox is an open source PBX distribution edition, it installs all dependent software on centeros (a Linux distribution version) and packs it into an ISO image, you only need to install a PC in 10 minutes to format and install it into a home PBX. however, if I want to develop on top, I need some third-party software, such as GCC, kernel-devel (for compilation), and subversion (for obtaining an updated software package ); trixbox is not installed by default. So I used the yum management software and referred to the use of yum, and found that it is very powerful. On the one hand, he can manage the software: 1. Install new software 2. update Software 3. on the other hand, you can also use the yum search software. Of course, the most common users can use Yum to update your system. This function is equivalent to automatic update of windows, patch your system. Before using it, we should first understand the repository. Generally, members of the community will maintain a software warehouse suitable for the operating system. In addition, some software authors may also provide a separate repository. The repository information is stored in the/etc/yum. Repos. d directory and several description files in your system. Repository maintainers generally publish their repository description files on their websites. The name of the Repository description file ends with. Repo. You must have the root permission to add files to this directory. The problem I encountered this time was that when I used Yum-y update to update my system, the following report was reported: http://download.skype.com/linux/repo...ta/repomd.xml: [errno 14] HTTP Error 404: Server: nginx/0.5.14trying other mirror. error: cannot open/read repomd. XML file for repository: Skype) Of course, the literal meaning is that the target server cannot be found, that is, the software in the software warehouse is obtained; but what I am confused about is, why update software on a Skype website? Later, I checked the information and found someone replied: You have installed a lot of useless repos and yum is not working properly because of that. post the output of this, that is, you have configured too many target software warehouse libraries, causing confusion when yum is searching. Sure enough, I checked: ls/etc/yum. Repos. D found a lot of *. Repo, and tried to open one. It is similar to an address configuration. We can see two seemingly official configuration files, which are retained and all other configuration files are deleted. Then execute Yum clean all OK, and then execute Yum-y update. I rely on it, and the download will continue, waiting for N for a long time. Yum does not require any routine maintenance. To ensure the operation speed of yum, you should disable or delete warehouses that are no longer needed and delete files in the yum cache, this saves hard disk space. You can set enable = 0 in the repository description file. The yum tool ignores the description file containing this setting. To completely delete a repository, you can delete it from/etc/yum. repos. delete related files in the D/directory, and delete related cache directories from/var/Cache/yum. By default, yum retains the software packages and software information files it downloads, in this case, you do not need to download the software file again. Run the command: Yum clean headers to delete all the software packages in the cache. Run the command: Yum clean packages.
